Problem: Evaluate the following expression when $c = 7$ and $d = 9$. $8$ $c$ $^2 + 4$ $d$ $ - 5$
Answer: Substitute $7$ for ${c}$ and $9$ for ${d}$ $ = 8{(7)}^2 + 4{(9)} - 5 $ Remember order of operations. Evaluate the exponent before you multiply. $ = 8(49) + 4{(9)} - 5 $ $ = 392 + 36 - 5 $ $ = 423$